Because of having operability, visualizability and flexibility, touch panels have been applied to most human-computer interaction means such as a personal mobile communication device (e.g. a smart phone), an integrated information terminal (e.g. a tablet computer), a super notebook computer and the like. Touch panels can be classified into four main types, which are resistive touch panels, capacitive touch panels, infrared touch panels and surface acoustic wave (SAW) touch panels, according to the principle of touch control. A capacitive touch panel, among the four main types, has a multi-touch function, a fast response time, a long service life, a high transmittance, and an excellent user experience of use. Meanwhile as the gradual improvement of the technology, a yield rate of a capacitive touch panel has been significantly increased, and a price of a capacitive touch panel has been decreasing, making it a major technical means of touch interaction for middle and small sized information terminals at the moment.
FIG. 1 shows a schematic plan view of an existing self-capacitive touch panel designed by employing an in-cell touch pattern. Each rectangle (with an actual size of 5 mm×5 mm) in FIG. 1 represents a touch control unit 1, which functions as both TX (transmitting signal) and RX (receiving signal). Each touch control unit 1 is connected to a pin of a driving chip (integrated circuit (IC)) 21 located at a bonding region of a flexible printed circuit (FPC) board 2 via a signal line 3. During an operation of a capacitive touch panel, a touch by a human finger may result in a change in a self-capacitance of a corresponding rectangular touch control unit 1, and a corresponding electrical signal is produced therewith. The driving chip 21 captures this electrical signal, and then a specific position at which the finger touch took place can be determined based on the change in the capacitance of the touch control unit 1, as shown in FIG. 2.
In FIG. 1, each touch control unit 1 is required to correspond to a signal line. The smaller the size of the rectangular touch control unit 1, the larger the number of the touch control units 1 that undergo changes in capacitance in a single touch operation, and the higher the sensitivity of touch control. However, too many touch control units 1 may lead to too many signal lines, so as to greatly increase space required for wiring in a fan-out region of the touch panel, resulting in an excessively wide bezel of the display device. Also, too many touch control units 1 may further increase power consumption, as well as the difficulty of FPC bonding.